Phono plugs of the type concerned with herein contain an electrically conductive center contact pin carried by a washer or disc of insulating material mounted within an electrically conductive shell member. The center contact pin is adapted to be plugged into an aperture-containing jack about which the shell member engages frictionally.
Prior art phono plugs generally have shell members which are made by drawing and shaping a piece of seamless tubing or the like. An insulating washer or disc through which extends the center contact pin is placed within the shell member and retained therein by internal annular shoulders which are biased against the disc by longitudinally squeezing or shortening the shell member, by indentations in the shell member at spaced intervals gripping the disc, by bent over lugs, or by a combination of the above. The coaxial cable is, generally attached to the center contact pin and shell member by soldering. Two such prior art phono plugs are disclosed in U.S. Pat. No. 3,723,949 and No. 3,295,094.
As is known to those skilled in the art, the currently used phono plugs including those described briefly above, while generally satisfactory in performance, involve complicated, excessive manufacturing steps, which do not lend themselves well to automatic assembly thereof and further are expensive to make.
Another problem associated with prior art phono plugs is that of strength and more particularly strength of the phono plug shell under forces exerted by the attached wires being flexed or bent.
Still another problem with phono plugs related to RF leakage through openings in the shell.
Accordingly, an important object of the present invention is to provide a phono plug which is inexpensive to make and can be mass produced on automatic machines.
Another object of the present invention is to attain important advantages and improvements in the structure and method of making phono plugs.
Still another object of the present invention is to provide a new and improved phono plug in which the components thereof are stamped and formed from planar sheets of conductive material and which contain thereon means to crimp such components onto the coaxial cable.
Yet another object of the present invention is to provide a phono plug having a stronger outer member or shell which resists the blending of wire transverse to the axis of the plug.
Still another object of the present invention is to provide a phono plug having reduced RF leakage therefrom.
Other objects, features and advantages of the invention will be readily apparent from the following description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts embodied in the disclosure and claims.